2016衛(wèi)生類職稱英語(yǔ)考試時(shí)態(tài)之現(xiàn)在完成時(shí)：

現(xiàn)在完成時(shí)：現(xiàn)在完成時(shí)表示一個(gè)發(fā)生在過(guò)去的、對(duì)現(xiàn)在仍有影響的動(dòng)作,或表示開(kāi)始在過(guò)去,并且一直延續(xù)到現(xiàn)在,甚至還可能延續(xù)下去的動(dòng)作。

①在完成時(shí)由“助動(dòng)詞have (has)+動(dòng)詞的過(guò)去分詞”構(gòu)成。

②表示發(fā)生在過(guò)去的對(duì)現(xiàn)在仍有影響的動(dòng)作時(shí),時(shí)間狀語(yǔ)有：already, yet, just, once, twice,ever, never,three times, before等。如：I have never seen such fine pictures before. (我以前從來(lái)沒(méi)有看過(guò)這么好的畫)/ He has just gone to England.(他剛?cè)ビ��?guó))

③表示在過(guò)去開(kāi)始一直延續(xù)到現(xiàn)在(可能延續(xù)下去)的動(dòng)作或狀態(tài)時(shí),時(shí)間狀語(yǔ)有：for (two years),since 1990, since (two weeks ago)和since引導(dǎo)的狀語(yǔ)從句。如：I have been away from my hometown for thirty years.(我離開(kāi)家鄉(xiāng)有30年了)/ Uncle Wang has worked in the factory since it opened.(自從這家工廠開(kāi)張,王叔叔一直在那兒工作)

④口語(yǔ)中have got往往表示have(有)的意思。如：They have got thousands of books in their library.(他們圖書館有上萬(wàn)本書)

⑤have been to與have gone to的區(qū)別：have gone to(“已經(jīng)去了”)表示人不在這里,have been to(“去過(guò)”)表示人在這里。如：--Where is Mr Li? –He has gone to the UK.(李先生在哪里?他去了英國(guó)。)/ --Do you know something about Beijing? –Yes,I have been to Beijing three times. (你知道北京的情況嗎?是的,我去過(guò)那里三次。)

⑥在完成時(shí)中,一個(gè)瞬間性動(dòng)詞(一次性動(dòng)作)不能與表示一段時(shí)間的狀語(yǔ)連用,此時(shí)須將該瞬間動(dòng)詞改為延續(xù)性動(dòng)詞或狀態(tài)動(dòng)詞。